1. Field of the Invention
The present invention relates to a main storage access control system for a virtual computing function system wherein a virtual computing function is realized by using a plurality of address modes in access operation for a main storage.
2. Description of the Related Arts
A virtual computing function system is well known in which a main storage has a plurality of virtual machine regions and a virtual machine monitoring region. In such a system, each of the virtual machine regions is under the control of the virtual machine monitoring region. A virtual computing function which is selected by the virtual machine monitoring region is executed by a central processor unit of a real computer.
In the virtual computing function system, an operating system for the virtual computing function system carries out a supervision of operations of the virtual computing function system. Where the result of supervision of n operation of a virtual computing function system affects another operation of the virtual computing function system, for example, in the case of a translation look aside buffer (TLB) or the like, a participation of a virtual machine monitoring region of the like takes place. However, the participation of such a virtual machine monitoring region tends to cause an extension of the time required for execution of the programs, and accordingly, tends to lower the efficiency of the virtual computing function system.
When a virtual machine monitoring region carries out an access to a virtual machine region, for the virtual machine monitoring region to represent the function of the virtual machine region, it is necessary to establish an address in accordance with the address mode which is designated by the virtual machine region.
Hence, when a virtual machine monitoring region carries out an access to a virtual machine region, it is necessary to discriminate the address mode of the virtual machine region and change the mode to the discriminated address mode or to carry out the equivalent address treatment, which causes a lowering of the efficiency of the control of the virtual computing function system because of the resultant undesirable increase of the overhead.